Dryers for drying food products, or the like, often require a large expenditure of energy in the operation thereof, particularly where heating means are primarily relied upon for the extraction of moisture from the material to be dried. Also, many drying methods rely upon the use of blowers, or the like, for the removal of moisture-laden air from around the material being dried. However, none make use of a vacuum tank partially filled with cold liquid and provided with a heat exchanger within the cold liquid for condensing vapor which rapidly escapes from the material being dried when the tank pressure is reduced below atmospheric pressure.